A market economy is indescribably vast and complex—its success depends on so many intricate, changing details all somehow being made to work smoothly together that the “facts” that are essential to its thriving cannot be catalogued with anywhere near the completeness that can be achieved by a 21st-century scientist studying and cataloging the “facts” that enable sparrows to fly. A sparrow is complex compared, say, to a limestone rock. Compared to the modern market economy, however, a sparrow is extremely simple.

A surge in the supply of steel in Detroit for the month of October 2012—an uptick in consumer demand for a specific color of car and a downtick in demand for another color—the possibility of using a new financial instrument to spread investment risks more widely—unexpected difficulties in hiring workers who possess a certain set of skills—an innovation that lowers the costs of advertising—an electrical failure that threatens to shut down for several days a section of a factory—a trucking company that discovers it underestimated the fuel costs of delivering 1,000 new automobiles to dealerships throughout New England. . . . Dealing with details such as these—details that Hayek called “the particular circumstances of time and place”—is not incidental to the success of a modern economy; it is of the essence.

Awareness of these facts, and of knowledge of workable options of how to respond to them, are key to the growth and continued success of any market economy. These facts are dealt with successfully only in market economies and only to the extent that individuals on the spot are free to respond to these facts as they, individually, see fit.

Yet no observer or planner or regulator can see and catalog all these highly specific facts. The facts—each of which must be dealt with—are far too numerous at any moment for an observing scientist to catalog even if that moment were to be frozen for decades. Greatly intensifying this complexity is the reality that these facts are forever changing. A moment from now many of these facts will be different from what they are at this moment.

Nevertheless, too many people, including politicians, continue to believe that because they can observe a handful of bulky facts about the economy, they can thereby know enough to intervene into that economy in ways that will improve its operation. That belief, though, is hubris. It’s very much like believing that you’ll fly if you simply strap on a pair of wings and commence to flapping madly.